25. Web pages: static webpages, dynamic webpages and tools to browse. Websites. Parts of url. Filenames in different oSs.

The World Wide Web, Web or WWW is a network of documents that works in a hypertext environment, i.e. using text that contains links, hyperlinks (a reference to a document that the reader can directly follow) to other documents.

The files, web pages, are stored in computers, which act as servers. A webpage is a document or resource of information that is suitable for the World Wide Web and can be accessed through a web browser and displayed on a computer screen. This information is usually in HTML (Hyper Text Markup Language) or XHTML (Extensible Hypertext Markup Language) format, and may provide navigation to other webpages via hypertext links. Webpages may consist of files of static text stored within the web server's file system (static webpages), or the web server may construct the (X)HTML for each webpage when it is requested by a browser (dynamic webpages).

Your computer, the client, uses a web browser, a special program to access and download web pages. The web pages are organized in websites, groups of pages located on the Web, maintained by a webmaster, the manager of a website.

To surf or navigate the Web, access and retrieve web pages or websites, you need a computer with an Internet connection and a web browser. After you have launched it, you must type the website address or URL (Uniform Resource Locator), which may look like this:

The different parts are separated by full stops (.) and forward slashes (/). When we say a URL, we say dot (.) and slash (/).

Within a single directory, filenames must be unique. Since filename also applies for subdirectories, it is also not possible to create equally named file and subdirectory entries in a single directory. However, two files in different directories may have the same name. In some operating systems, such as MS-DOS, Microsoft Windows, and classic Mac OS, upper-case letters and lower-case letters in file names are considered the same, so that, for example, the file names "MyName" and "myname" would be considered the same, and a directory could not contain a file with the name "MyName" and another file with the name "myname". The file systems in those operating systems are called "case-insensitive". In most file systems in Unix-like systems, however, upper-case and lower-case are considered different, so that files “MyName” and “myname” would be valid names for different files concurrently in the same directory. Those file systems are called "case-sensitive". To find interesting sites you can use search engines, where the website information is compiled by spiders, computer-robot programs that collect information from sites by using keywords, Some web portals - websites that offer all types of services, e.g. email, forums, search engines, etc. - are also good starting points. The most relevant website addresses can be stored in your computer using the bookmarks or favourites function in your browser. Websites usually have a beginning page or home page. From this starting point you can navigate by clicking your mouse on hyperlinks in texts or images.